Ms Bryan said the loss of the crossing patrols will have a "massive impact".
"The traffic doesn't stop for me so what makes them think it will stop for parents, whether there is a zebra crossing or not. In the mornings, it's a fighting battle every day," she said.
City councillors previously used their community funds to keep Ms Bryan's job until the next academic year, but nothing has been put in place yet for September.
Angus Ellis, a Labour councillor and cabinet member for environment and transport at Peterborough City Council, said: "A proposal to remove the school crossing patrol service at four schools in Peterborough was agreed as part of the council's budget for 2024/25.
"Crossings and or speed restrictions such as at 20mph zones are in place at each of the schools and we are also providing road safety education for pupils."
The petition will close on 11 June and will then be submitted to a cabinet meeting.
If it reaches 500 signatures before the deadline, it will also be eligible for submission to a full council meeting.
Last month parents held a protest outside the Eye Primary School calling for the decision to be reviewed.